A histologist has the function of taking unprocessed tissue samples and preparing tissue slides therefrom for diagnosis by a pathologist. The importance of this work cannot be overstated since the quality of the tissue slide prepared by the histologist is critical to the ability of the pathologist to evaluate and diagnose the tissue for abnormal pathologies such as cancer or leukemia from the slide. Any small increases in the quality of the tissue slide for the pathologist's evaluation, thus have a huge impact in preventing mis-diagnosis and in minimizing the stress and fatigue of the pathologist and cost to the health care system. If the tissue slide is of unacceptable or poor quality, time and money is lost in preparing a new slide. The time lost could be critical to the patient's health by causing an undue delay in the patient's treatment.
The histologist faces difficulties in preparing a proper tissue slide because of the thinness of the tissue section to be transferred to the tissue slide. The tissue section should optimally be only one cell (e.g., approximately two to four microns) in thickness.
For example, to prepare a tissue slide for the pathologist to diagnose for leukemia, the histologist must take a sample of drawn bone marrow and cut it into thin sections. However, the bone marrow can be very brittle, like dust, and portions can flake off the sections both during and after its cutting. The resulting throughput (i.e., amount and coherency) of the tissue section actually transferred onto the slide is typically low, and may be of too marginal or poor quality for the pathologist to use. The histologist is forced to reject that section, and cut and select additional sections until a suitable section is obtained. This procedure is time consuming, inefficient, and costly.
In order to increase the quality of the tissue section transferred onto the slide, a few histologists try attempt to rub ammonium hydroxide onto the surface of the tissue sample from which the tissue section is to be cut prior to cutting. This is typically performed with an ammonium hydroxide soaked pad. However, there are several problems with this technique. Ammonium hydroxide, which is caustic, evaporates quickly and will rapidly penetrate the surrounding atmosphere. This exposes the histologist to noxious fumes which irritate the sinuses and produce eye watering and also can cause a base burn if it gets on the skin. Furthermore, because of the quick evaporation, the histologist is forced to constantly re-soak the gauze with additional ammonium hydroxide. Additionally, because ammonium hydroxide is a CAP/OSHA scheduled hazardous substance, the gauze must be soaked under a ventilation hood, typically located in a laboratory away from where the slicing takes place. Thus, this procedure is unsafe, inefficient, time consuming, and unpleasant to the histologist. As a result, fewer and fewer histologist's are using ammonium hydroxide to increase the throughput of the tissue section transferred onto the slide.
Additionally, laboratory training for histologist's, and other laboratory technicians, has increasingly shifted to training in the use of off-the-shelf products. For example, histology students in the past were taught how to make required chemical agents such as Schiff's Reagent, Hematoxylin, and Carbol Fuchsin. However, all of these are now sold in off-the-shelf product form and their method of manufacture is no longer being taught to histology students. Since no commercially available off-the-shelf, ready to use, product currently exists to train students to use ammonium hydroxide in preparing their slides, fewer and fewer histology students are even being taught of the beneficial use of ammonium hydroxide in increasing the quality of their prepared slides. Thus, the art is dying.
In view of the foregoing, a need exists for an apparatus that a histologist can conveniently use while preparing a tissue slide to increase the quality of the slide. It would be beneficial if the apparatus allowed the histologist to safely apply ammonium hydroxide to a tissue sample to increase the resulting throughput of a tissue section cut from the sample transferred onto a slide with minimal exposure to the ammonium hydroxide. It would further be beneficial if such an apparatus could help to minimize re-cut requests thereby facilitating the prompt treatment of patients. It would further be beneficial if the apparatus minimized the amount of ammonium hydroxide evaporated to the atmosphere and maximized the amount of ammonium hydroxide for applying to the embedded tissue sample. It would additionally be beneficial if the apparatus provided a ready to use product which could immediately be used as an off-the-shelf product, without preparation or assembly. Such an apparatus could be ordered by laboratories, and the like, so as to be readily and easily accessible to a large percentage of the population of histologists and histological students.